The present invention relates to engine cooling and more particularly to an improved cooling unit for an engine.
Vehicular engines, whether internal combustion or fuel cell based, generate heat during the energy conversion process, which heats up the components of the engine. In some instances, this heat can damage or significantly wear the engine components. A cooling circuit is provided to avoid excessive heating of the engine components.
The cooling circuit circulates a flow of cooling fluid through the engine and a radiator. The cooling fluid is in heat exchange relationship with the components of the engine. Heat is transferred from the engine to the cooling fluid. The cooling fluid flows from the engine and through a radiator. The radiator acts as a heat exchanger enabling heat transfer from the cooling fluid to atmosphere. In this manner, the cooling fluid is continuously warmed by the engine and cooled by the radiator to reduce engine temperature.
Air flow through the radiator draws heat from the atmosphere immediately surrounding the radiator. This air flow is necessary to enable the radiator to sufficiently transfer heat from the cooling fluid. During periods of vehicle movement, natural air flow is induced. That is to say, as the vehicle moves forward, air naturally flows through the vehicle. This natural air flow increases or decreases corresponding to vehicle speed. At higher speeds, the natural air flow draws sufficient heat from the radiator. However, during periods of rest or driving at lower speeds there is insufficient natural air flow through the radiator.
Traditional vehicle cooling units include either an axial blower positioned in front of the radiator, an axial blower positioned behind the radiator or both. The axial blower positioned in front of the radiator is operable to blow air through the radiator. The axial blower positioned behind the radiator is operable to draw air through the radiator. During periods when the natural air flow is too light to sufficiently draw heat from the radiator, the axial blower or blowers are activated to induce air flow through the radiator.
Such traditional systems retain specific disadvantages. In the case of a single axial blower positioned behind the radiator, the air flow induced by the single blower may be insufficient. In the case of an axial blower positioned in front of the radiator, the axial blower itself may block significant amount of natural air flow induced by vehicle motion. As a result, the axial blower(s) are frequently switched on to compensate for the lack of natural air flow through the radiator. The frequent operation of the axial blower(s) is inefficient and increases wear of the axial blower(s).
The present invention provides a cooling unit including a radiator. The cooling unit further includes a blower that draws air through the radiator along a longitudinal axis and a cross-flow fan that draws air along a lateral axis. The cross-flow fan forces air through the radiator along the longitudinal axis.
In one feature, the cross-flow fan includes a flap that is movable between an open position to enable air flow from the cross-flow fan and a closed position to block air flow from the cross-flow fan. A biasing member biases the flap in the open position. Further, when the flap is in the closed position the cross-flow fan stops operating.
In another feature, when in the open position the flap partially blocks natural air flow into the radiator.
In yet another feature, an intake extends along the lateral axis and functions to draw air through the cross-flow fan.
In still another feature, air forced through the radiator and air drawn through the radiator along the longitudinal axis cools a fluid flowing through the radiator.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.